     (def at available-tiles)
     (def ss screen-state)
     (def f frame)
+    (def cvs canvas)
     (.add (.getContentPane frame) canvas)
     (setup-fullscreen frame)
     (handle-drags canvas screen-state)

(defn awt-image [^TaggedImage tagged-image]
  (.getImage (ImagePlus. "" (ImageUtils/makeProcessor tagged-image))))

(defn get-tile [[nx ny nz nc nt nzoom]]
  (grab-tagged-image))

(defn add-tile [tile-map indices]
  (assoc tile-map indices (get-tile indices)))

(defn add-to-available-tiles [available-tiles indices]
  (send-off available-tiles add-tile indices))

;; gui utilities




(defn test-tile [nx ny]
  (add-to-available-tiles at 0 [nx ny 0 0 0]))

(defn test-tiles [nx ny]
  (doseq [i (range nx) j (range ny)]
